request: use bufio.Reader and bufio.Writer

Before:
```
goos: linux
goarch: amd64
pkg: github.com/thiagokokada/hyprland-go
cpu: AMD Ryzen 7 PRO 4750U with Radeon Graphics
BenchmarkSplash
BenchmarkSplash-16    	  35851	    34729 ns/op
PASS
ok  	github.com/thiagokokada/hyprland-go	1.595s``
```

Bufio.Reader:
```
goos: linux
goarch: amd64
pkg: github.com/thiagokokada/hyprland-go
cpu: AMD Ryzen 7 PRO 4750U with Radeon Graphics
BenchmarkSplash
BenchmarkSplash-16    	  30976	    38695 ns/op
PASS
ok  	github.com/thiagokokada/hyprland-go	1.604s
```

Bufio.Reader + Bufio.Writer:
```
goos: linux
goarch: amd64
pkg: github.com/thiagokokada/hyprland-go
cpu: AMD Ryzen 7 PRO 4750U with Radeon Graphics
BenchmarkSplash
BenchmarkSplash-16    	  29901	    40494 ns/op
PASS
ok  	github.com/thiagokokada/hyprland-go	1.630s
```

request.go

@@ -1,6 +1,7 @@
 package hyprland
 
 import (
+	"bufio"
 	"bytes"
 	"encoding/json"
 	"errors"
@@ -240,16 +241,20 @@ func (c *RequestClient) RawRequest(request RawRequest) (response RawResponse, er
 			request,
 		)
 	}
-	_, err = conn.Write(request)
+
+	writer := bufio.NewWriter(conn)
+	_, err = writer.Write(request)
 	if err != nil {
 		return nil, fmt.Errorf("error while writing to socket: %w", err)
 	}
+	writer.Flush()
 
 	// Get the response back
 	rbuf := bytes.NewBuffer(nil)
 	sbuf := make([]byte, BUF_SIZE)
+	reader := bufio.NewReader(conn)
 	for {
-		n, err := conn.Read(sbuf)
+		n, err := reader.Read(sbuf)
 		if err != nil {
 			if err == io.EOF {
 				break

request_test.go

@@ -325,6 +325,15 @@ func TestSplash(t *testing.T) {
 	testCommand(t, c.Splash, "")
 }
 
+func BenchmarkSplash(b *testing.B) {
+	if c == nil {
+		b.Skip("HYPRLAND_INSTANCE_SIGNATURE not set, skipping test")
+	}
+	for i := 0; i < b.N; i++ {
+		c.Splash()
+	}
+}
+
 func TestWorkspaces(t *testing.T) {
 	testCommand(t, c.Workspaces, []Workspace{})
 }